The notorious blob, a mass of unusually warm water stretching from Alaska to Mexico, has crept its way back onto the radar as NOAA scientists try to determine what the ocean anomaly might cause as it travels up and down the coast.

Initially, the blob formed because winter storms that normally mix surface waters with deep cold water were not as strong and made the usual transport of cool water from the north weaker as well, which meant the normal degree of winter cooling over the north Pacific did not occur, according to NOAA and Humboldt State University fisheries oceanographer Eric Bjorkstedt.

A high pressure system known as the “Ridiculously Resilient Ridge” (RRR) blocked storms from coming across the Pacific along their normal track and also contributed to California’s historic drought. According to Bjorkstedt, the RRR is considered a consequence of changes in atmospheric and climate dynamics in the western tropical Pacific. The blob was first seen in late 2013 and has impacted marine life in the Pacific Northwest.

The blob is known to disrupt marine life and aquatic ecosystems with warmer than normal water that can extend 1,000 feet below the surface.

Nicholas Bond, a research meteorologist at the University of Washington, Seattle, first gave the blob its name and also wrote the first extensive scientific report on it.

“For the last couple years, it has certainly evolved. It’s an usual pattern in terms of where the water was warmer,” Bond said. “In 2015, it was especially extreme. I’d be very surprised if it got that bad this time. On the other hand, the conditions are similar to how they were then and that could contribute to a lot of problems.”

Bond said the blob created abnormalities that lead to the deaths of marine mammals, sea birds, and was linked to harmful algal blooms which caused large concentrations of domoic acid in sardines and anchovies in 2014 and Dungeness crabs in 2015 across the California coast.

“The chemistry of the ocean is changing too, it’s a bunch of moving parts and some organisms are affected while others can adapt to it,” Bond said.

On the North Coast, Bjorkstedt does observations of the warming with a sampling program every month. He said the water isn’t getting warmer, but instead it is not cooling off like it should. This is because the cooler water below the surface has increased in temperature making it difficult to cool the surface water which means the water stays abnormally warm for longer.

“The concern is what are the effects of the blob in the winter and spring,” Bjorkstedt said. “At any given point in the north Pacific, there was less cold water coming from the north and less cold water mixing to the surface.”

Conditions for juvenile salmon might just have less favorable conditions, according to Bjorkstedt which are contributed to the warmer ocean temperatures.

“Salmon can always move north but it may not be a good year for them if they’re quote ‘stuck in the Klamath’ because the ocean might not be as favorable as their natural prey becomes less abundant or lower quality than they’re used to.”

Bond said the warmer water caused pretty significant changes in the salmon’s food web, with more copepods, a main food source for salmon, becoming smaller and less lipid rich.